NetBSD/lib/libc/stdlib/malloc.3

.\"	$NetBSD: malloc.3,v 1.9 1999/03/22 19:44:57 garbled Exp $
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.\"     from: @(#)malloc.3	8.1 (Berkeley) 6/4/93
.\"
.Dd June 4, 1993
.Dt MALLOC 3
.Os
.Sh NAME
.Nm malloc
.Nd general memory allocation function
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.Fd #include <stdlib.h>
.Ft void *
.Fn malloc "size_t size"
.Sh DESCRIPTION
The
.Fn malloc
function allocates uninitialized space for an object whose
size is specified by
.Fa size .
The
.Fn malloc
function maintains multiple lists of free blocks according to size, allocating
space from the appropriate list.
.Pp
The allocated space is
suitably aligned (after possible pointer
coercion) for storage of any type of object. If the space is of
.Em pagesize
or larger, the memory returned will be page-aligned.
.Sh RETURN VALUES
The
.Fn malloc
function returns
a pointer to the allocated space if successful; otherwise
a null pointer is returned.
.Sh SEE ALSO
.Xr brk 2 ,
.Xr alloca 3 ,
.Xr calloc 3 ,
.Xr free 3 ,
.Xr getpagesize 3 ,
.Xr memory 3 ,
.Xr realloc 3
.Sh STANDARDS
The
.Fn malloc
function conforms to
.St -ansiC .
.Sh BUGS
The current implementation of
.Fn malloc
does not always fail gracefully when system
memory limits are approached.
It may fail to allocate memory when larger free blocks could be broken
up, or when limits are exceeded because the size is rounded up.
It is optimized for sizes that are powers of two.